US20090044794A1 - Inducer speed control method for combustion furnace - Google Patents
Inducer speed control method for combustion furnace Download PDFInfo
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- US20090044794A1 US20090044794A1 US11/893,242 US89324207A US2009044794A1 US 20090044794 A1 US20090044794 A1 US 20090044794A1 US 89324207 A US89324207 A US 89324207A US 2009044794 A1 US2009044794 A1 US 2009044794A1
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- blower
- firing rate
- furnace
- speed
- combustion
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- 238000002485 combustion reaction Methods 0.000 title claims abstract description 33
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- 239000000567 combustion gas Substances 0.000 claims abstract description 30
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- 230000001939 inductive effect Effects 0.000 claims 3
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- 239000002737 fuel gas Substances 0.000 description 1
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Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/002—Regulating air supply or draught using electronic means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/08—Regulating air supply or draught by power-assisted systems
- F23N3/082—Regulating air supply or draught by power-assisted systems using electronic means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/24—Preventing development of abnormal or undesired conditions, i.e. safety arrangements
- F23N5/242—Preventing development of abnormal or undesired conditions, i.e. safety arrangements using electronic means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/20—Control of fluid heaters characterised by control inputs
- F24H15/242—Pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/20—Control of fluid heaters characterised by control inputs
- F24H15/254—Room temperature
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/30—Control of fluid heaters characterised by control outputs; characterised by the components to be controlled
- F24H15/305—Control of valves
- F24H15/31—Control of valves of valves having only one inlet port and one outlet port, e.g. flow rate regulating valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/30—Control of fluid heaters characterised by control outputs; characterised by the components to be controlled
- F24H15/345—Control of fans, e.g. on-off control
- F24H15/35—Control of the speed of fans
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/30—Control of fluid heaters characterised by control outputs; characterised by the components to be controlled
- F24H15/355—Control of heat-generating means in heaters
- F24H15/36—Control of heat-generating means in heaters of burners
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/30—Control of fluid heaters characterised by control outputs; characterised by the components to be controlled
- F24H15/395—Information to users, e.g. alarms
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H15/00—Control of fluid heaters
- F24H15/40—Control of fluid heaters characterised by the type of controllers
- F24H15/414—Control of fluid heaters characterised by the type of controllers using electronic processing, e.g. computer-based
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H3/00—Air heaters
- F24H3/02—Air heaters with forced circulation
- F24H3/06—Air heaters with forced circulation the air being kept separate from the heating medium, e.g. using forced circulation of air over radiators
- F24H3/08—Air heaters with forced circulation the air being kept separate from the heating medium, e.g. using forced circulation of air over radiators by tubes
- F24H3/087—Air heaters with forced circulation the air being kept separate from the heating medium, e.g. using forced circulation of air over radiators by tubes using fluid fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H9/00—Details
- F24H9/20—Arrangement or mounting of control or safety devices
- F24H9/2064—Arrangement or mounting of control or safety devices for air heaters
- F24H9/2085—Arrangement or mounting of control or safety devices for air heaters using fluid fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2223/00—Signal processing; Details thereof
- F23N2223/46—Identification
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2225/00—Measuring
- F23N2225/04—Measuring pressure
- F23N2225/06—Measuring pressure for determining flow
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2233/00—Ventilators
- F23N2233/02—Ventilators in stacks
- F23N2233/04—Ventilators in stacks with variable speed
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2237/00—Controlling
- F23N2237/10—High or low fire
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2241/00—Applications
- F23N2241/06—Space-heating and heating water
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/005—Regulating air supply or draught using electrical or electromechanical means
Definitions
- Efficient combustion furnaces for heating, ventilating and air conditioning (HVAC) equipment applications are typically provided with a motor driven so-called ventilating or inducer blower which draws air through the combustion passageways of the furnace heat exchanger to improve the efficiency of the combustion and heat transfer processes and to prolong the life of the furnace.
- Selection of the proper speeds of the inducer blower drive motor for multistage combustion furnaces, in particular, has been a somewhat nettlesome problem.
- Combustion furnaces which include electronic controls have been developed wherein the inducer blower motor speed is controlled based on opening and closing of pressure switches which measure the pressures developed by the inducer blower at one or more particular points in the air flowpath.
- the present invention provides an improved method of determining proper inducer or ventilating blower speeds for multistage combustion furnaces for HVAC applications
- a method of controlling the inducer or ventilating blower speed and the pressures generated thereby has been developed wherein a control system for the furnace is programmed to provide, initially, a default speed for a medium or intermediate furnace firing rate, for example.
- a learn routine is provided for the medium firing rate and a multiple of the learned medium firing rate inducer blower speed value is applied to set a blower motor speed for a low firing rate and a high firing rate based on the speed at the medium or intermediate firing rate.
- the lower inducer blower speed limits and upper speed limits can be defined by this relationship and set as multiples of the learned medium or intermediate firing rate inducer blower speed. Inducer blower speeds determined in this manner allow for proper furnace operation with virtually any type of venting system normally expected to be connected to the furnace.
- a method of controlling a combustion furnace including a multistage furnace and, particularly, a three-stage furnace wherein the furnace control system learns a medium speed for the inducer blower motor to which is applied a multiple or multiplier (less than one and greater than one) to provide inducer blower speeds for a furnace low firing rate and a high firing rate.
- the multiplier may be different for different models of furnace, but may be provided to the control system for a particular furnace when it leaves the point of manufacture or at a later time. Accordingly, a learning procedure for the inducer blower motor speed at low firing rates and high firing rates is not required and the so-called target inducer blower speeds for low and high firing rates are actually relatively closer to a learned speed than arbitrarily selected default speeds.
- a method of determining inducer blower speeds wherein one or more inducer blower speeds for particular firing rates of a furnace may be preset and based on respective multiples or multipliers of another selected motor speed and which multiples may be developed through testing the flow resistance of various lengths and configurations of furnace venting systems likely to be applied to respective different furnace models.
- the multipliers would possibly be different for different furnace models and could be provided to a particular furnace control system as part of a set of control and operating parameters programmed in the control system directly or on a separate information or “personality” module associated with the furnace prior to or after shipment from the point of manufacture.
- the invention contemplates the provision of a furnace control system and method of operation wherein only a single pressure switch or pressure sensor would be required to properly operate the furnace at different inducer blower speeds.
- FIG. 1 is a perspective view, in somewhat schematic form, of a multistage combustion furnace operable in accordance with the method of the present invention
- FIG. 2 is a schematic diagram of a control system for the furnace illustrated in FIG. 1 ;
- FIG. 3 is a flow diagram illustrating certain steps in the method of the present invention.
- FIG. 1 there is illustrated a combustion furnace operable by the method of the present invention and generally designated by the numeral 10 .
- the furnace 10 is illustrated as including a generally rectangular boxlike cabinet 12 having an air inlet opening 12 a adapted to be connected to a return air duct 12 b .
- Cabinet 12 also includes a discharge air opening 12 c for discharging air through suitable ducting to an enclosed space 13 . Airflow to and from the furnace 10 is via suitable ducting and in accordance with the direction of flow indicated by the arrows 13 a and 13 b.
- Combustion furnace 10 includes plural side-by-side gaseous fuel fired heat exchangers 14 , each being provided with a serpentine combustion gas flow passage 14 a, one shown, and each discharging combustion gases and ventilation air to a plenum 14 b in a known manner. Additional details of combustion gas furnaces of the general type referred to herein are described in U.S. Pat. No. 5,060,722 to Zdenek, et al. and U.S. Pat. No. 5,309,892 to Lawlor, et al., both of which are assigned to the assignee of the present invention.
- Air circulated to and from the space 13 is propelled through cabinet 12 by a motor driven air circulation blower 15 disposed within the cabinet, as illustrated in FIG. 1 .
- Combustion fuel is delivered to the heat exchangers 14 at respective burners 16 which are supplied with fuel, such as natural gas, by way of a manifold 17 connected to a control valve 18 having a suitable electric controller 20 associated therewith.
- An electric motor driven inducer or ventilating blower 22 is operably associated with the plenum 14 b for drawing air and combustion gases through the heat exchangers 14 in a known manner.
- Blower 22 is controlled by an electric drive motor 23 which includes a suitable speed control system to be described in further detail herein.
- a temperature sensor or so-called thermostat 24 is disposed in the space 13 and is operably connected to a furnace control system 26 disposed at the cabinet 12 .
- Control system 26 may include an interface 28 for use by a user or service technician for setting certain control parameters and observing certain operating conditions of furnace 10 .
- Control system 26 includes, for example, a microcontroller 30 for receiving signals from the thermostat 24 and for controlling operation of the blowers 15 and 22 and the fuel flow control valve 18 .
- Suitable pressure sensors or switches three shown by way of example, are designated by numerals 32 a, 32 b and 32 c in FIG. 1 and are shown mounted on plenum 14 b for sensing the pressure therein.
- the pressure sensors 32 a, 32 b and 32 c may be characterized as pressure switches which open and close at fixed or adjustable preset pressures and are suitably disposed within the flow path of the combustion gases and air being circulated by the blower 22 .
- switches 32 a , 32 b and 32 c may be selected as compared with the location illustrated.
- the switches or sensors 32 a , 32 b and 32 c may be replaced by a single variable pressure sensor which is operable to output signals to the control system 26 , indicating the pressure associated with the air and combustion products flowstream flowing through the heat exchangers 14 .
- vent system or flue pipe 25 suitably connected to the blower 22 and normally having a length sufficient to conduct combustion gases to the exterior of the structure or building in which the furnace 10 is located.
- the so-called venting system including the flue pipe 25
- the flue pipe 25 may be of various lengths and configurations and may include one or more pipe elements which are curved.
- a certain resistance to flow of combustion products would be associated with the configuration of a particular venting system.
- each furnace design or configuration, including its venting system would have a set of inducer blower motor speeds corresponding to furnace and venting system flow characteristics and required to produce desired pressures and flow rates through the heat exchanger passages 14 a and plenum 14 b.
- the pressures that the inducer blower 22 is capable of producing in the combustion gas flowpath, including the burner or heat exchanger passages 14 a and the plenum 14 b, will vary with the speed of the blower and its drive motor 23 .
- control system 26 which includes a microprocessor 30 operable to receive signals from the thermostat 24 and the pressure switches 32 a , 32 b and 32 c, as well as a limit temperature sensor or switch 33 disposed in cabinet 12 .
- Microprocessor 30 is operable to control the operation of motor 15 a by way of a motor control circuit 15 b, the operation of valve 18 and the operation of inducer blower motor 23 by way of its own speed control circuit 23 a .
- User interface 28 may be used to observe certain operating parameters of the control system 26 and make selections of such parameters via a suitable user operable keypad 28 a and a visual display 28 b.
- microprocessor 30 may include certain memory circuits 30 a and 30 b which are operable to receive information from a separate circuit of a device 35 which may be releasably connected to the microprocessor 30 and sometimes referred to as a so-called personality module.
- the personality module 35 may be of a type described in co-pending U.S. patent application Ser. No. 11/717,466 filed Mar. 13, 2007, by Robert W. Helt, et al. and assigned to the assignee of the present invention.
- thermostat 24 includes, for example, temperature and humidity sensors 24 a and 24 b disposed within the space 13 whereby thermostat 24 is operable to communicate signals to the microprocessor 30 to initiate operation of the furnace 10 under a so-called “call for heat” signal, such operation being well-known to those skilled in the art.
- blower motor speeds for driving blower 22 sufficient to provide required pressures generated by the blower may be predetermined.
- the blower speeds for motor 23 may also be determined and which are sufficient to generate the required pressures.
- pressures are normally measured as negative (below atmospheric pressure) in inches of water column.
- a high pressure is actually a greater amount of vacuum being pulled by the blower 22 within the plenum 14 c or otherwise within the flowpath of ventilation air and combustion gases proceeding through the heat exchangers 14 .
- a low furnace firing rate speed required of the blower 22 for generating a low firing rate pressure may be determined and the low firing rate speed is related to the medium firing rate speed required of the blower 22 for providing the required pressures at the medium firing rate.
- a relationship between the medium firing rate blower speed and the low firing rate blower speed may also be calculated, since it is a multiple of the learned medium firing rate blower speed.
- a multiplier may be applied to the learned medium speed value to determine the low firing rate speed of the blower 22 . Still further, since the position of the control valve 18 and the fuel gas pressure in manifold 17 is correlated with the pressure produced by the blower 22 within the furnace 10 , unreasonably low manifold pressures which could create undesirable combustion characteristics are avoided.
- the linear relationship between inducer blower speed and the configuration of the vent system, such as the conduit 25 provides for determining the speed of blower motor 23 to produce suitable pressures in the furnace 10 commensurate with a high furnace firing rate and based on the learned medium firing rate blower speed.
- the relationship between the required pressures generated by the blower 22 for a particular firing rate, such as a medium firing rate, and the blower motor speed required to obtain such pressures may be used to set the inducer blower speeds and attendant pressures for a continuously variable firing rate, based on a table of blower speeds versus vent system effective length for the vent system or conduit 25 . This data can be furnished from the module 35 and input to the processor 30 for a particular furnace 10 , as previously mentioned.
- blower motor 23 is set to operate at a predetermined medium firing rate default speed and a low speed (low firing rate) pressure switch position is checked at step 42 . If the low firing rate pressure switch is not closed, if such a switch is being used, a fault signal is set by control system 26 at step 44 . If the low firing rate pressure switch is closed, then the medium firing rate pressure switch is checked at step 46 . If the medium firing rate pressure switch is not closed, the blower motor 23 speed is incremented a predetermined minimum amount at step 48 and a status of the medium firing rate pressure switch is checked again at step 50 .
- step 50 the medium firing rate pressure switch is not closed, steps 48 and 50 are repeated until the switch is closed. If the medium firing rate pressure switch is closed at step 46 , the process proceeds to step 52 and the speed of blower motor 23 is decremented a minimum predetermined amount and the status of the medium firing rate pressure switch is checked again at step 54 . Steps 52 and 54 are repeated until the medium firing rate pressure switch opens. Accordingly, within a relatively narrow range of pressure conditions for the furnace medium or intermediate firing rate, a suitable speed for blower 22 is established and monitored by the processor 30 via the motor control circuit 23 a.
- control system 26 will query the database stored in memories 30 a and/or 30 b to set the low firing rate blower speed for blower motor 23 at step 56 and then the process may proceed to set the high firing rate speed for blower motor 23 at step 58 .
- the furnace 10 then will continue to run at step 60 while blower motor speed for blower 22 is monitored together with monitoring of the pressure switches 32 a , 32 b and 32 c.
- control system 26 may utilize a pressure sensor in place of plural pressure switches, which sensor continuously monitors pressures in a selected location or locations of the ventilating air and combustion gas flowpath through heat exchangers 14 .
- the pressure settings at which action is taken may be carried out by the control system 26 by monitoring the pressure signal input from such a sensor to the microprocessor 30 .
- the medium firing rate speed of blower 22 could be set based on a limited range of suitable pressures for the medium firing rate. Blower speeds could be incremented or decremented from the aforementioned medium firing rate default speed until the pressure sensed by such a pressure sensor was within the predetermined range.
- the present invention contemplates that a single pressure switch may be used to set the medium firing rate blower motor speed for blower 22 followed by the steps indicated in FIG. 3 .
- steps 42 and 44 would be eliminated from the process shown in FIG. 3 and, at a call for heat, control over the blower 22 would immediately proceed from the medium default speed to the medium learned speed based on the process of FIG. 3 to establish a pressure within the furnace combustion system suitable for the specified firing rate, and the low and high firing rate blower speeds would then be determined in accordance with the process shown in FIG. 3 .
Abstract
Description
- Efficient combustion furnaces for heating, ventilating and air conditioning (HVAC) equipment applications are typically provided with a motor driven so-called ventilating or inducer blower which draws air through the combustion passageways of the furnace heat exchanger to improve the efficiency of the combustion and heat transfer processes and to prolong the life of the furnace. Selection of the proper speeds of the inducer blower drive motor for multistage combustion furnaces, in particular, has been a somewhat nettlesome problem. Combustion furnaces which include electronic controls have been developed wherein the inducer blower motor speed is controlled based on opening and closing of pressure switches which measure the pressures developed by the inducer blower at one or more particular points in the air flowpath.
- Moreover, so-called learning algorithms have been developed which require setting a blower default speed for multistage furnaces for the low firing rate and high firing rate which is the first speed that the inducer motor will be controlled to when a call for the low firing rate or high firing rate is signaled to the furnace controller. The inducer blower then “learns” a speed based on opening and closing of the pressure switches. Still further, typically, a low speed limit is defined in the control system program to avoid the combustion gas control valve closing prematurely. U.S. Pat. Nos. 6,257,870 and 6,377,426 to Hugghins, et al. and assigned to the assignee of the present invention disclose and claim methods for setting inducer blower operating speeds.
- However, for multistage furnaces including, for example, three stage furnaces, it is desirable to maintain the inducer flow pressures above a predetermined setpoint which is particularly important at low firing rates to avoid low combustion gas pressures which could create undesirable combustion characteristics. This occurs because the gas valve output pressure tracks the inducer or system pressures in the aforementioned type of furnace. Still further, it is desirable to simplify the “learning” of the inducer blower motor speeds for respective furnace firing rates in multistage furnaces, including three stage furnaces. In accordance with the present invention, improvements in determining and setting inducer blower speeds and operating pressures have been realized and attendant advantages enjoyed as a result.
- The present invention provides an improved method of determining proper inducer or ventilating blower speeds for multistage combustion furnaces for HVAC applications
- In accordance with one aspect of the present invention, a method of controlling the inducer or ventilating blower speed and the pressures generated thereby has been developed wherein a control system for the furnace is programmed to provide, initially, a default speed for a medium or intermediate furnace firing rate, for example. A learn routine is provided for the medium firing rate and a multiple of the learned medium firing rate inducer blower speed value is applied to set a blower motor speed for a low firing rate and a high firing rate based on the speed at the medium or intermediate firing rate. These multiples may be based on the realization that there is a substantially linear relationship between properly set inducer blower speed and the flow resistance caused by the venting system connected to the furnace. Thus, the lower inducer blower speed limits and upper speed limits can be defined by this relationship and set as multiples of the learned medium or intermediate firing rate inducer blower speed. Inducer blower speeds determined in this manner allow for proper furnace operation with virtually any type of venting system normally expected to be connected to the furnace.
- In accordance with another aspect of the present invention there is provided a method of controlling a combustion furnace, including a multistage furnace and, particularly, a three-stage furnace wherein the furnace control system learns a medium speed for the inducer blower motor to which is applied a multiple or multiplier (less than one and greater than one) to provide inducer blower speeds for a furnace low firing rate and a high firing rate. The multiplier may be different for different models of furnace, but may be provided to the control system for a particular furnace when it leaves the point of manufacture or at a later time. Accordingly, a learning procedure for the inducer blower motor speed at low firing rates and high firing rates is not required and the so-called target inducer blower speeds for low and high firing rates are actually relatively closer to a learned speed than arbitrarily selected default speeds.
- In accordance with a further aspect of the present invention a method of determining inducer blower speeds is provided wherein one or more inducer blower speeds for particular firing rates of a furnace may be preset and based on respective multiples or multipliers of another selected motor speed and which multiples may be developed through testing the flow resistance of various lengths and configurations of furnace venting systems likely to be applied to respective different furnace models. The multipliers would possibly be different for different furnace models and could be provided to a particular furnace control system as part of a set of control and operating parameters programmed in the control system directly or on a separate information or “personality” module associated with the furnace prior to or after shipment from the point of manufacture.
- Still further, the invention contemplates the provision of a furnace control system and method of operation wherein only a single pressure switch or pressure sensor would be required to properly operate the furnace at different inducer blower speeds.
- Those skilled in the art will further appreciate the above-mentioned advantages and superior features of the invention, together with other important aspects thereof, upon reading the detailed description which follows in conjunction with the drawings.
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FIG. 1 is a perspective view, in somewhat schematic form, of a multistage combustion furnace operable in accordance with the method of the present invention; -
FIG. 2 is a schematic diagram of a control system for the furnace illustrated inFIG. 1 ; and -
FIG. 3 is a flow diagram illustrating certain steps in the method of the present invention. - In the description which follows like elements are marked through the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale and certain elements are shown in schematic or somewhat generalized form in the interest of clarity and conciseness.
- Referring to
FIG. 1 , there is illustrated a combustion furnace operable by the method of the present invention and generally designated by thenumeral 10. Thefurnace 10 is illustrated as including a generally rectangularboxlike cabinet 12 having an air inlet opening 12 a adapted to be connected to areturn air duct 12 b.Cabinet 12 also includes a discharge air opening 12 c for discharging air through suitable ducting to an enclosedspace 13. Airflow to and from thefurnace 10 is via suitable ducting and in accordance with the direction of flow indicated by thearrows Combustion furnace 10 includes plural side-by-side gaseous fuel firedheat exchangers 14, each being provided with a serpentine combustion gas flow passage 14 a, one shown, and each discharging combustion gases and ventilation air to aplenum 14 b in a known manner. Additional details of combustion gas furnaces of the general type referred to herein are described in U.S. Pat. No. 5,060,722 to Zdenek, et al. and U.S. Pat. No. 5,309,892 to Lawlor, et al., both of which are assigned to the assignee of the present invention. - Air circulated to and from the
space 13 is propelled throughcabinet 12 by a motor drivenair circulation blower 15 disposed within the cabinet, as illustrated inFIG. 1 . Combustion fuel is delivered to theheat exchangers 14 atrespective burners 16 which are supplied with fuel, such as natural gas, by way of a manifold 17 connected to acontrol valve 18 having a suitableelectric controller 20 associated therewith. An electric motor driven inducer or ventilatingblower 22 is operably associated with theplenum 14b for drawing air and combustion gases through theheat exchangers 14 in a known manner. Blower 22 is controlled by anelectric drive motor 23 which includes a suitable speed control system to be described in further detail herein. A temperature sensor or so-calledthermostat 24 is disposed in thespace 13 and is operably connected to afurnace control system 26 disposed at thecabinet 12. -
Control system 26 may include aninterface 28 for use by a user or service technician for setting certain control parameters and observing certain operating conditions offurnace 10.Control system 26 includes, for example, amicrocontroller 30 for receiving signals from thethermostat 24 and for controlling operation of theblowers flow control valve 18. Suitable pressure sensors or switches, three shown by way of example, are designated bynumerals FIG. 1 and are shown mounted onplenum 14 b for sensing the pressure therein. Thepressure sensors blower 22. Other locations of the sensors orswitches sensors control system 26, indicating the pressure associated with the air and combustion products flowstream flowing through theheat exchangers 14. - Combustion products discharged from the
furnace 10 are conducted through a vent system orflue pipe 25 suitably connected to theblower 22 and normally having a length sufficient to conduct combustion gases to the exterior of the structure or building in which thefurnace 10 is located. Accordingly, the so-called venting system, including theflue pipe 25, may be of various lengths and configurations and may include one or more pipe elements which are curved. Thus, a certain resistance to flow of combustion products would be associated with the configuration of a particular venting system. Accordingly, each furnace design or configuration, including its venting system, would have a set of inducer blower motor speeds corresponding to furnace and venting system flow characteristics and required to produce desired pressures and flow rates through the heat exchanger passages 14 a andplenum 14 b. Of course, the pressures that theinducer blower 22 is capable of producing in the combustion gas flowpath, including the burner or heat exchanger passages 14 a and theplenum 14 b, will vary with the speed of the blower and itsdrive motor 23. - Referring now to
FIG. 2 , there is illustrated a schematic diagram ofcontrol system 26 which includes amicroprocessor 30 operable to receive signals from thethermostat 24 and thepressure switches switch 33 disposed incabinet 12.Microprocessor 30 is operable to control the operation ofmotor 15 a by way of amotor control circuit 15 b, the operation ofvalve 18 and the operation ofinducer blower motor 23 by way of its ownspeed control circuit 23 a.User interface 28 may be used to observe certain operating parameters of thecontrol system 26 and make selections of such parameters via a suitable useroperable keypad 28 a and avisual display 28 b. Still further,microprocessor 30 may includecertain memory circuits device 35 which may be releasably connected to themicroprocessor 30 and sometimes referred to as a so-called personality module. Thepersonality module 35 may be of a type described in co-pending U.S. patent application Ser. No. 11/717,466 filed Mar. 13, 2007, by Robert W. Helt, et al. and assigned to the assignee of the present invention. Still further,thermostat 24 includes, for example, temperature andhumidity sensors space 13 wherebythermostat 24 is operable to communicate signals to themicroprocessor 30 to initiate operation of thefurnace 10 under a so-called “call for heat” signal, such operation being well-known to those skilled in the art. - For a particular furnace design and capacity for a three-stage furnace, for example, blower motor speeds for driving
blower 22 sufficient to provide required pressures generated by the blower may be predetermined. Moreover, for various configurations of the furnace combustion products venting system, including the vent conduit orpipe 25, for a particular furnace design, the blower speeds formotor 23 may also be determined and which are sufficient to generate the required pressures. With respect to determining pressures, such pressures are normally measured as negative (below atmospheric pressure) in inches of water column. Hence, a high pressure is actually a greater amount of vacuum being pulled by theblower 22 within theplenum 14 c or otherwise within the flowpath of ventilation air and combustion gases proceeding through theheat exchangers 14. Since it has been determined there is a linear relationship between the required inducer blower speed for a predetermined amount of pressure generated by theblower 22 and the length or configuration of the vent system, including the vent conduit orpipe 25, a low furnace firing rate speed required of theblower 22 for generating a low firing rate pressure may be determined and the low firing rate speed is related to the medium firing rate speed required of theblower 22 for providing the required pressures at the medium firing rate. Moreover, if a learned medium firing rate inducer blower speed is obtained, then a relationship between the medium firing rate blower speed and the low firing rate blower speed may also be calculated, since it is a multiple of the learned medium firing rate blower speed. Accordingly, by basing the low firing rate inducer blower speed on a learned medium firing rate inducer blower speed which has been learned for a particular furnace installation, a multiplier may be applied to the learned medium speed value to determine the low firing rate speed of theblower 22. Still further, since the position of thecontrol valve 18 and the fuel gas pressure in manifold 17 is correlated with the pressure produced by theblower 22 within thefurnace 10, unreasonably low manifold pressures which could create undesirable combustion characteristics are avoided. - In addition to establishing a low firing rate speed of
blower 22 and pressures within theheat exchangers 14 produced thereby, the linear relationship between inducer blower speed and the configuration of the vent system, such as theconduit 25, provides for determining the speed ofblower motor 23 to produce suitable pressures in thefurnace 10 commensurate with a high furnace firing rate and based on the learned medium firing rate blower speed. Moreover, the relationship between the required pressures generated by theblower 22 for a particular firing rate, such as a medium firing rate, and the blower motor speed required to obtain such pressures, may be used to set the inducer blower speeds and attendant pressures for a continuously variable firing rate, based on a table of blower speeds versus vent system effective length for the vent system orconduit 25. This data can be furnished from themodule 35 and input to theprocessor 30 for aparticular furnace 10, as previously mentioned. - One preferred method of setting the respective speeds for the
inducer blower 22 is indicated inFIG. 3 . At “power-up” or start, when a call for heat is received atstep 40,blower motor 23 is set to operate at a predetermined medium firing rate default speed and a low speed (low firing rate) pressure switch position is checked atstep 42. If the low firing rate pressure switch is not closed, if such a switch is being used, a fault signal is set bycontrol system 26 atstep 44. If the low firing rate pressure switch is closed, then the medium firing rate pressure switch is checked atstep 46. If the medium firing rate pressure switch is not closed, theblower motor 23 speed is incremented a predetermined minimum amount atstep 48 and a status of the medium firing rate pressure switch is checked again atstep 50. - If, at
step 50, the medium firing rate pressure switch is not closed, steps 48 and 50 are repeated until the switch is closed. If the medium firing rate pressure switch is closed atstep 46, the process proceeds to step 52 and the speed ofblower motor 23 is decremented a minimum predetermined amount and the status of the medium firing rate pressure switch is checked again atstep 54.Steps blower 22 is established and monitored by theprocessor 30 via themotor control circuit 23 a. Once the medium firing rate blower motor speed forblower 22 is established thecontrol system 26 will query the database stored inmemories 30 a and/or 30 b to set the low firing rate blower speed forblower motor 23 atstep 56 and then the process may proceed to set the high firing rate speed forblower motor 23 atstep 58. Thefurnace 10 then will continue to run atstep 60 while blower motor speed forblower 22 is monitored together with monitoring of the pressure switches 32 a, 32 b and 32 c. - Alternatively, the
control system 26 may utilize a pressure sensor in place of plural pressure switches, which sensor continuously monitors pressures in a selected location or locations of the ventilating air and combustion gas flowpath throughheat exchangers 14. The pressure settings at which action is taken may be carried out by thecontrol system 26 by monitoring the pressure signal input from such a sensor to themicroprocessor 30. For example, the medium firing rate speed ofblower 22 could be set based on a limited range of suitable pressures for the medium firing rate. Blower speeds could be incremented or decremented from the aforementioned medium firing rate default speed until the pressure sensed by such a pressure sensor was within the predetermined range. - Still further, the present invention contemplates that a single pressure switch may be used to set the medium firing rate blower motor speed for
blower 22 followed by the steps indicated inFIG. 3 . In other words, steps 42 and 44 would be eliminated from the process shown inFIG. 3 and, at a call for heat, control over theblower 22 would immediately proceed from the medium default speed to the medium learned speed based on the process ofFIG. 3 to establish a pressure within the furnace combustion system suitable for the specified firing rate, and the low and high firing rate blower speeds would then be determined in accordance with the process shown inFIG. 3 . - Those skilled in the art will recognize that an improved process and system for operating a multistage combustion furnace of the so-called inducer or ventilating type is provided by the present invention. Conventional engineering materials, components and procedures may be carried out to practice the invention. Although a preferred embodiment has been described in detail herein, those skilled in the art will also recognize that various substitutions and modifications may be made without departing from the scope and spirit of the appended claims.
Claims (17)
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US11/893,242 US9261277B2 (en) | 2007-08-15 | 2007-08-15 | Inducer speed control method for combustion furnace |
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Citations (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4251025A (en) * | 1979-07-12 | 1981-02-17 | Honeywell Inc. | Furnace control using induced draft blower and exhaust stack flow rate sensing |
US4729207A (en) * | 1986-09-17 | 1988-03-08 | Carrier Corporation | Excess air control with dual pressure switches |
US4842190A (en) * | 1988-04-22 | 1989-06-27 | Ortech Industries, Inc. | Control circuit for a forced-air heating system |
US5248083A (en) * | 1992-11-09 | 1993-09-28 | Honeywell Inc. | Adaptive furnace control using analog temperature sensing |
US5271556A (en) * | 1992-08-25 | 1993-12-21 | American Standard Inc. | Integrated furnace control |
US5331944A (en) * | 1993-07-08 | 1994-07-26 | Carrier Corporation | Variable speed inducer motor control method |
US5340028A (en) * | 1993-07-12 | 1994-08-23 | Carrier Corporation | Adaptive microprocessor control system and method for providing high and low heating modes in a furnace |
US5418438A (en) * | 1993-02-26 | 1995-05-23 | General Electric Company | Draft inducer air flow control |
US5616995A (en) * | 1993-02-22 | 1997-04-01 | General Electric Company | Systems and methods for controlling a draft inducer for a furnace |
US5680021A (en) * | 1993-02-22 | 1997-10-21 | General Electric Company | Systems and methods for controlling a draft inducer for a furnace |
US5682826A (en) * | 1993-02-22 | 1997-11-04 | General Electric Company | Systems and methods for controlling a draft inducer for a furnace |
US5732691A (en) * | 1996-10-30 | 1998-03-31 | Rheem Manufacturing Company | Modulating furnace with two-speed draft inducer |
US5791332A (en) * | 1996-02-16 | 1998-08-11 | Carrier Corporation | Variable speed inducer motor control method |
US5957064A (en) * | 1997-11-28 | 1999-09-28 | Barry; Louis T. | Method and apparatus for operating a multiple hearth furnace |
US6161535A (en) * | 1999-09-27 | 2000-12-19 | Carrier Corporation | Method and apparatus for preventing cold spot corrosion in induced-draft gas-fired furnaces |
US6257870B1 (en) * | 1998-12-21 | 2001-07-10 | American Standard International Inc. | Gas furnace with variable speed draft inducer |
US6321744B1 (en) * | 1999-09-27 | 2001-11-27 | Carrier Corporation | Modulating furnace having a low stage with an improved fuel utilization efficiency |
US7101172B2 (en) * | 2002-08-30 | 2006-09-05 | Emerson Electric Co. | Apparatus and methods for variable furnace control |
US7293718B2 (en) * | 2001-09-10 | 2007-11-13 | Varidigm Corporation | Variable output heating and cooling control |
US7320362B2 (en) * | 2004-06-28 | 2008-01-22 | Honeywell International Inc. | Dynamic fluid delivery system with compensation |
US20080073440A1 (en) * | 2005-02-23 | 2008-03-27 | Butler William P | Interactive control system for an hvac system |
US20080124667A1 (en) * | 2006-10-18 | 2008-05-29 | Honeywell International Inc. | Gas pressure control for warm air furnaces |
US20080127963A1 (en) * | 2006-12-01 | 2008-06-05 | Carrier Corporation | Four-stage high efficiency furnace |
US20080127962A1 (en) * | 2006-12-01 | 2008-06-05 | Carrier Corporation | Pressure switch assembly for a furnace |
-
2007
- 2007-08-15 US US11/893,242 patent/US9261277B2/en active Active
Patent Citations (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4251025A (en) * | 1979-07-12 | 1981-02-17 | Honeywell Inc. | Furnace control using induced draft blower and exhaust stack flow rate sensing |
US4729207A (en) * | 1986-09-17 | 1988-03-08 | Carrier Corporation | Excess air control with dual pressure switches |
US4842190A (en) * | 1988-04-22 | 1989-06-27 | Ortech Industries, Inc. | Control circuit for a forced-air heating system |
US5271556A (en) * | 1992-08-25 | 1993-12-21 | American Standard Inc. | Integrated furnace control |
US5248083A (en) * | 1992-11-09 | 1993-09-28 | Honeywell Inc. | Adaptive furnace control using analog temperature sensing |
US5616995A (en) * | 1993-02-22 | 1997-04-01 | General Electric Company | Systems and methods for controlling a draft inducer for a furnace |
US5680021A (en) * | 1993-02-22 | 1997-10-21 | General Electric Company | Systems and methods for controlling a draft inducer for a furnace |
US5682826A (en) * | 1993-02-22 | 1997-11-04 | General Electric Company | Systems and methods for controlling a draft inducer for a furnace |
US5418438A (en) * | 1993-02-26 | 1995-05-23 | General Electric Company | Draft inducer air flow control |
US5557182A (en) * | 1993-02-26 | 1996-09-17 | General Electric Company | System and methods for controlling a draft inducer to provide a desired operating area |
US5331944A (en) * | 1993-07-08 | 1994-07-26 | Carrier Corporation | Variable speed inducer motor control method |
US5340028A (en) * | 1993-07-12 | 1994-08-23 | Carrier Corporation | Adaptive microprocessor control system and method for providing high and low heating modes in a furnace |
US5791332A (en) * | 1996-02-16 | 1998-08-11 | Carrier Corporation | Variable speed inducer motor control method |
US5732691A (en) * | 1996-10-30 | 1998-03-31 | Rheem Manufacturing Company | Modulating furnace with two-speed draft inducer |
US5957064A (en) * | 1997-11-28 | 1999-09-28 | Barry; Louis T. | Method and apparatus for operating a multiple hearth furnace |
US6257870B1 (en) * | 1998-12-21 | 2001-07-10 | American Standard International Inc. | Gas furnace with variable speed draft inducer |
US6377426B2 (en) * | 1998-12-21 | 2002-04-23 | American Standard International Inc. | Gas furnace with variable speed draft inducer |
US6161535A (en) * | 1999-09-27 | 2000-12-19 | Carrier Corporation | Method and apparatus for preventing cold spot corrosion in induced-draft gas-fired furnaces |
US6321744B1 (en) * | 1999-09-27 | 2001-11-27 | Carrier Corporation | Modulating furnace having a low stage with an improved fuel utilization efficiency |
US7293718B2 (en) * | 2001-09-10 | 2007-11-13 | Varidigm Corporation | Variable output heating and cooling control |
US7101172B2 (en) * | 2002-08-30 | 2006-09-05 | Emerson Electric Co. | Apparatus and methods for variable furnace control |
US7320362B2 (en) * | 2004-06-28 | 2008-01-22 | Honeywell International Inc. | Dynamic fluid delivery system with compensation |
US20080073440A1 (en) * | 2005-02-23 | 2008-03-27 | Butler William P | Interactive control system for an hvac system |
US20080124667A1 (en) * | 2006-10-18 | 2008-05-29 | Honeywell International Inc. | Gas pressure control for warm air furnaces |
US20080127963A1 (en) * | 2006-12-01 | 2008-06-05 | Carrier Corporation | Four-stage high efficiency furnace |
US20080127962A1 (en) * | 2006-12-01 | 2008-06-05 | Carrier Corporation | Pressure switch assembly for a furnace |
Cited By (36)
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US20090297997A1 (en) * | 2008-05-27 | 2009-12-03 | Honeywell International Inc. | Combustion blower control for modulating furnace |
US8070481B2 (en) * | 2008-05-27 | 2011-12-06 | Honeywell International Inc. | Combustion blower control for modulating furnace |
US8545214B2 (en) | 2008-05-27 | 2013-10-01 | Honeywell International Inc. | Combustion blower control for modulating furnace |
US20140023976A1 (en) * | 2008-05-27 | 2014-01-23 | Honeywell International, Inc. | Combustion blower control for modulating furnace |
US8764435B2 (en) | 2008-07-10 | 2014-07-01 | Honeywell International Inc. | Burner firing rate determination for modulating furnace |
US10376999B2 (en) | 2010-01-15 | 2019-08-13 | Lennox Industries Inc. | Alternative-fuel gas orifice having principal-fuel gas orifice temperature profile and a heating, ventilation and air conditioning system incorporating the same |
US20110174201A1 (en) * | 2010-01-15 | 2011-07-21 | Lennox Industries, Incorporated | Furnace, a method for operating a furnace and a furnace controller configured for the same |
CN102155796A (en) * | 2010-01-15 | 2011-08-17 | 雷诺士工业股份有限公司 | A furnace, a method for operating a furnace and a furnace controller configured for the same |
US10253981B2 (en) * | 2010-01-15 | 2019-04-09 | Lennox Industries Inc. | Furnace, a method for operating a furnace and a furnace controller configured for the same |
US9429338B2 (en) | 2010-01-15 | 2016-08-30 | Lennox Industries Inc. | Furnace header box having blocked condensation protection, a furnace including the header box and a blocked condensation protection system |
US20170350595A1 (en) * | 2010-01-15 | 2017-12-07 | Lennox Industries Inc. | Furnace, a method for operating a furnace and a furnace controller configured for the same |
US9815154B2 (en) | 2010-01-15 | 2017-11-14 | Lennox Industries Inc. | Furnace header box having blocked condensation protection, a furnace including the header box and a blocked condensation protection system |
US9765965B2 (en) | 2010-01-15 | 2017-09-19 | Lennox Industries Inc. | Furnace, a method for operating a furnace and a furnace controller configured for the same |
US9541303B2 (en) | 2010-01-15 | 2017-01-10 | Lennox Industries Inc. | Alternative-fuel gas orifice having principal-fuel gas orifice temperature profile and a heating, ventilation and air conditioning system incorporating the same |
US9335045B2 (en) * | 2010-01-15 | 2016-05-10 | Lennox Industries Inc. | Furnace, a method for operating a furnace and a furnace controller configured for the same |
US20110271880A1 (en) * | 2010-05-04 | 2011-11-10 | Carrier Corporation | Redundant Modulating Furnace Gas Valve Closure System and Method |
US10254008B2 (en) | 2010-06-22 | 2019-04-09 | Carrier Corporation | Thermos at algorithm for fully modulating furnaces |
US9513003B2 (en) * | 2010-08-16 | 2016-12-06 | Purpose Company Limited | Combustion apparatus, method for combustion control, board, combustion control system and water heater |
US20120037096A1 (en) * | 2010-08-16 | 2012-02-16 | Takagi Industrial Co., Ltd. | Combustion apparatus, method for combustion control, combustion control board, combustion control system and water heater |
US8925541B2 (en) * | 2010-10-05 | 2015-01-06 | Carrier Corporation | Method and system for controlling an inducer in a modulating furnace |
US20120080023A1 (en) * | 2010-10-05 | 2012-04-05 | Carrier Corporation | Method And System For Controlling An Inducer In A Modulating Furnace |
US20120125268A1 (en) * | 2010-11-24 | 2012-05-24 | Grand Mate Co., Ltd. | Direct vent/power vent water heater and method of testing for safety thereof |
US9249988B2 (en) * | 2010-11-24 | 2016-02-02 | Grand Mate Co., Ted. | Direct vent/power vent water heater and method of testing for safety thereof |
US10443840B2 (en) * | 2011-05-12 | 2019-10-15 | RM Manifold Group, Inc. | Reversible draft controllers and exhaust systems incorporating same |
US10094591B2 (en) | 2011-08-15 | 2018-10-09 | Carrier Corporation | Furnace control system and method |
US20130071261A1 (en) * | 2011-09-16 | 2013-03-21 | Grand Mate Co., Ltd. | Method of detecting safety of water heater |
US9086068B2 (en) * | 2011-09-16 | 2015-07-21 | Grand Mate Co., Ltd. | Method of detecting safety of water heater |
US9453648B2 (en) | 2012-03-02 | 2016-09-27 | Honeywell International Inc. | Furnace with modulating firing rate adaptation |
US8876524B2 (en) | 2012-03-02 | 2014-11-04 | Honeywell International Inc. | Furnace with modulating firing rate adaptation |
US10344975B2 (en) * | 2012-07-24 | 2019-07-09 | Lennox Industries Inc. | Combustion acoustic noise prevention in a heating furnace |
US20210215340A1 (en) * | 2019-07-30 | 2021-07-15 | Lg Electronics Inc. | Rpm control method for inducer for gas furnace |
US11592176B2 (en) * | 2019-07-30 | 2023-02-28 | Lg Electronics Inc. | RPM control method for inducer for gas furnace |
US20210063025A1 (en) * | 2019-08-30 | 2021-03-04 | Lennox Industries Inc. | Method and system for protecting a single-stage furnace in a multi-zone system |
US20210277908A1 (en) * | 2020-03-09 | 2021-09-09 | Regal Beloit America, Inc. | Control system for electric fluid moving systems |
US11879472B2 (en) * | 2020-03-09 | 2024-01-23 | Regal Beloit America, Inc. | Control system for electric fluid moving systems |
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